Worst case you end up with the Japan version, from a Japan based company. No big deal. You won't get the US warranty so you'll have to either pay for repairs or ship it overseas. Canon USA may do the repair, don't know, but you'll have to pay for it.
So you took a chance, saving the money upfront and hope you don't have any issues. How long is the US warranty good for anyway? 1 Year? You'll want the Mark II in a year anyway

For some people its worth the risk, for others it isn't. I wouldn't have done it, but it may work out. Don't be too upset if you don't get a US warranty though, because like I said, its only good for the first year anyway, and bodies have limited shelf lives as it is. If you have to put in for a repair, you'll lose what you saved on the initial cost, depending on the nature of the repair. A lens on the other hand sticks around for much longer, so I wouldn't play games with something like that, but bodies, whatever, you'll be fine.
And a 6 isn't the worst rating you can get. The real scammers have less than 1. As long as it comes with a battery you're doing alright.
All this being said isn't an endorsement. I only buy from B&H. But don't beat yourself up too much if you don't get the US warranty and they won't let you return it.